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France is the United States’ oldest ally. Dating back to the United States’ founding, France’s friendship was crucial to the nascent nation’s very survival. This shared history makes American politicians’ glaring absence from last weekend’s rally in Paris all the more galling. Yes, on Friday, Secretary of State John Kerry gave France “a hug” along with James Taylor’s performance of “You’ve Got a Friend,” but the Obama Administration needs to do far more.

The French aided the United States in our war for liberty; we should we stand beside them now as they defend theirs.

“The preservation of the sacred fire of liberty, and the destiny of the republican model of government,” George Washington wrote in 1789, are “staked on the experiment entrusted to the hands of the American people.” The world still looks to the United States to continue this experiment in republican government. And by not going to Paris, President Obama and our leaders failed the American people by neglecting to stand with France against Islamic extremists’ attacks on one of those sacred liberties: freedom of expression.

The absence of the president, vice president, and other top officials from the rally sent a dangerous message. It showed the world that the United States’ leaders cannot be counted on to stand up for one of its core beliefs; it indicated that the nation is selective in its support, even for its oldest ally. And if history has taught us anything, it is that messages matter.

During the United States’ battle for independence, General George Washington astutely recognized that he could not win the war solely through military tactics. He had to inspire the American people and rest of the world to believe in the righteousness of the patriots’ fight for liberty. Unlike other generals of his day who orchestrated battles from afar, Gen. Washington was at the front lines, courageously risking his life to fight alongside his troops. It was precisely such symbolism that moved the patriots to sacrifice for the liberties we enjoy today. And we need our leaders to continue to be at the front lines of America’s ongoing ideological struggle.

In 1778, Benjamin Franklin and the American patriots convinced France to join their fight for independence by entering with them into the “Treaty of Alliance and a Treaty of Amity and Commerce.” As the fledgling United States struggled against Britain, the patriots were desperate for French troops, munitions, ships, and funds.

Sure, the French did not aid the American patriots due to any great love of liberty. The French were still governed by their own king, after all. Instead, the French government helped for selfish reasons: they sought to defeat France’s old British foes. The Americans were the enemies of their enemies, as the ancient proverb goes. And in a long, global war that cost thousands of American and French lives and nearly bankrupted both nations, the allies beat the mightiest empire on earth.

Yes, America’s relationship with France has had its ups and downs since then: the United States refused to aid the French revolutionaries when they overthrew their own monarch in the 18th century because the Americans deemed them too radical. But that rift was repaired by 1885, when France gave the United States the Statue of Liberty to commemorate the nations’ commitment to liberty. Then during World War I and again in World War II, the United States stood with France in defense of liberty, for which Charles de Gaulle symbolically returned the favor with his very conspicuous presence as our nation grieved following the Kennedy assassination.

Though the two nations’ histories may be mixed and their approaches to free speech somewhat varied, the United States and France’s interests are largely aligned now as we confront another threat to freedom.

Over the past two and half centuries, our mutual foe has transformed from a monarchy to a fundamentalist ideology; but the fight for liberty nevertheless rages on.

Since the Revolutionary War, American republican ideology has spread throughout the globe. The patriots’ triumph soon ignited uprisings in France, Ireland, the Netherlands, Poland, Haiti, and Latin America, and, over time, values such as free expression came to take deeper root, fueled in part by the American example. Over the following centuries, these principles were adopted to varying degrees around the world, helping to lead to a level of liberty the likes of which the earth has never previously enjoyed.

Far from an inevitable progression, the United States’ founding principles were tested and faced ruin numerous times throughout the ages—by the European monarchies, by the fascists, and by the communists. But against each, the ideology of individual liberty triumphed as American troops and their allies fought oppressive regimes.

But now those principles are threatened again by a competing ideology: militant Islamic extremism. With ISIS being the chief example, people are turning by the thousands towards an ideology of oppression and violence.

Ideological wars are not won by guns alone. They are won by ideas. That’s why the president missed a critical opportunity last weekend to reaffirm the nation’s support for one of our most fundamental ideals: freedom of expression. As Gen. Washington put it, if “the freedom of Speech may be taken away,… dumb and silent we may be led, like sheep, to the Slaughter.”

It is time for the nation’s leadership to unequivocally demonstrate America’s commitment to our core principles. Through words and actions the president must galvanize the American people and the world to defend freedom of expression. He needs to go to the front lines, which currently include Paris, and as Gen. Washington phrased it, “show the whole world that a freeman, contending for his liberty on his own ground, is superior to any slavish mercenary on earth.” Gen. Washington understood that America’s enemies only respond to forceful resolve.

If President Obama does not visibly stand up for American principles of liberty alongside the nation’s allies, we will lose ground to latest threat to the continuing American experiment—and that “sacred fire of liberty” will darken.